Positive photosensitive composition and method of forming resist pattern

ABSTRACT

A positive photosensitive composition comprises: (A) 5 to 20 parts by weight of the total amount of at least one compound that generates an acid upon irradiation with an actinic ray; and (B) 100 parts by weight of the total amount of at least one fluorine atom-containing resin having a group that increases a solubility of the resin in an alkaline developer by the action of an acid.

This is a continuation of application Ser. No. 10/895,824 filed Jul. 22,2004. The entire disclosure of the prior application, application Ser.No. 10/895,824, is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a positive photosensitive compositionsuitable for use in microlithography processes such as the production ofULSIs or high-capacity microchips and in other photofabricationprocesses. More particularly, the invention relates to a positivephotosensitive composition capable of forming a high-resolution patternwith a vacuum ultraviolet light having a wavelength of 193 nm orshorter.

2. Description of the Related Art

The degree of integration in integrated circuits is increasing more andmore, and it has become necessary to form an ultrafine pattern having aline width of a quarter micrometer or smaller in the production ofsemiconductor substrates for ULSIs or the like. One of the knowntechniques for enhancing the fineness of such patterns is to use anexposure light having a shorter wavelength in resist pattern formation.

For example, in the production of semiconductor elements having anintegration degree of up to 64 megabits, the i-line (365 nm) from ahigh-pressure mercury lamp has hitherto been used as an exposure light.Many compositions comprising a novolak resin and a naphthoquinonediazidecompound as a photosensitive substance have been developed as positiveresists for use with the exposure light, and have given sufficientresults in forming patterns having line widths down to about 0.3 μm. Onthe other hand, in the production of semiconductor elements having anintegration degree of 256 megabits or higher, KrF excimer laser light(248 nm) has been used as an exposure light in place of the i-line.

Furthermore, use of ArF excimer laser light (193 nm), which is anexposure light having an even shorter wavelength, and use of F₂ excimerlaser light (157 nm) for forming a pattern having a line width of 0.1 μmor smaller are recently being investigated for the purpose of producingsemiconductor elements having an integration degree of 1 gigabit orhigher.

With the use of such exposure lights having shorter wavelengths, thecomponents of resist materials and the structures of compounds for usetherein are changing considerably. For example, the related-art resistscomprising a novolak resin and a naphthoquinonediazide compound have hadthe following problem. Since these resists show considerable absorptionin a far ultraviolet region including 248 nm, the light is less apt tosufficiently reach the resist bottom. As a result, the resists have lowsensitivity and give tapered patterns only.

In order to eliminate such problems, a so-called chemical amplificationtype resist has been developed. This resist is a composition whichcomprises a combination of: a resin, as the main component, which has apoly(hydroxystyrene) backbone showing reduced absorption in a 248 nmregion and is protected by acid-dissociable groups; and a compound whichgenerates an acid upon irradiation with far ultraviolet light(photo-acid generator). The chemical amplification type resist changesin solubility in a developing solution based on a decomposition reactioncatalyzed by the acid generated in exposed areas, and can hence showhigh sensitivity and give high-resolution patterns.

However, in the case of using ArF excimer laser light (193 nm), even thechemical amplification type resist has been unable to have sufficientperformances because compounds having aromatic groups intrinsically showconsiderable absorption in a wavelength region including 193 nm.

An improvement in the chemical amplification type resist has beenattempted in order to overcome that problem. In this improvement, anacid-decomposable resin which has, incorporated in the polymer mainchain or side chains thereof, alicyclic structures showing no absorptionat 193 nm is used in place of the acid-decomposable resin comprisingpoly(hydroxystyrene) as the backbone.

However, it has been found that when F₂ excimer laser light (157 nm) isused, even the alicyclic resin is insufficient in obtaining a desiredpattern of 0.1 μm or finer because the resin shows considerableabsorption in a 157 nm region. Under these circumstances, a resin havingfluorine atoms (perfluorinated structure) incorporated therein wasreported to have sufficient transparency at 157 nm, in Proc. SPIE., Vol.3678, p. 13 (1999). Effective structures of such fluororesins areproposed in Proc. SPIE., Vol. 3999, p. 330 (2000), Proc. SPIE., Vol.3999, p. 357 (2000), Proc. SPIE., Vol. 3999, p. 365 (2000), WO-00/17712,German Patent 1,005,466, Published U.S. Patent Application No.2001/0,018,162 A2, etc.

However, the related-art resists containing a fluororesin have beendesired to be further improved in sensitivity, line edge roughnessdiminution, and profile.

SUMMARY OF THE INVENTION

Accordingly, an object of the invention is to provide a positivephotosensitive composition which has high sensitivity when farultraviolet light having a wavelength of 250 nm or shorter, inparticular, ArF excimer laser light or F₂ excimer laser light, is usedas an exposure light and which is excellent in line edge roughnessdiminution and profile.

The invention has the following constitutions, with which that object ofthe invention is accomplished.

(1) A positive photosensitive composition comprising:

(A) 5 to 20 parts by weight of the total amount of at least one compoundthat generates an acid upon irradiation with an actinic ray; and (B) 100parts by weight of the total amount of at least one fluorineatom-containing resin having a group that increases a solubility of theresin in an alkaline developer by the action of an acid.

(2) The positive photosensitive composition as described in (1) above,wherein the resin (B) has a main chain to which at least one fluorineatom is bonded.

Preferred embodiments of the invention are further shown below.

(3) The positive photosensitive composition as described in (1) above,wherein the resin (B) has a repeating unit having from 1 to 3 groupsrepresented by formula (A-1):

wherein R_(1a) represents a hydrogen atom, an alkyl group, a cycloalkylgroup, an acyl group, an alkoxycarbonyl group, or a group whichdissociates by the action of an acid.

(4) The positive photosensitive composition as described in (1) above,wherein the resin (B) has a fluorine atom-containing repeating unit anda repeating unit with no fluorine atom.

(5) The positive photosensitive composition as described in (4) above,wherein the repeating unit with no fluorine atom is at least onerepeating unit selected from (a) to (c):

-   -   (a) monocyclic or polycyclic, alicyclic hydrocarbon        structure-having, acid-dissociating repeating unit;    -   (b) lactone structure-having repeating unit;    -   (c) monocyclic or polycyclic, alicyclic hydrocarbon structure        and hydroxyl group-having repeating unit.

(6) The positive photosensitive composition as described in any of (1)to (5) above, wherein the compound (A) is a sulfonium salt.

(7) The positive photosensitive composition as described in any of (1)to (5) above, wherein the compound (A) is a sulfonium salt of afluorine-substituted aliphatic sulfonic acid having 4 to 8 carbon atoms.

(8) A method of forming a resist pattern comprising: coating thepositive photosensitive composition described in any of (1) to (7) aboveon a substrate, to form a resultant coating; irradiating the resultantcoating with an actinic ray, to form an irradiated coating; anddeveloping the irradiated coating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a two-beam interference exposureexperimental apparatus.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be explained below in detail.

With respect to expressions of groups (atomic groups) in thisspecification, the expressions which include no statement as to whetherthe groups are substituted or unsubstituted imply both of groups havingno substituents and groups having one or more substituents. For example,the term “alkyl group” implies not only an alkyl group having nosubstituents (unsubstituted alkyl group) but also an alkyl group havingone or more substituents (substituted alkyl group).

The positive photosensitive composition of the invention comprises (A) 5to 20 parts by weight of the total amount of at least one compound thatgenerates an acid upon irradiation with an actinic ray; and (B) 100parts by weight of the total amount of at least one fluorineatom-containing resin having a group that increases a solubility of theresin in an alkaline developer by the action of an acid (a group thatdissociate by the action of an acid to enhance solubility in an alkalinedeveloper).

[1] (A) Compound Generating Acid Upon Irradiation with Actinic Ray

The compound which generates an acid upon irradiation with an actinicray (photo-acid generator) to be used in the invention can be onesuitably selected from photoinitiators for cationic photopolymerization,photoinitiators for radical photopolymerization, photodecolorants oroptical color changers for dyes, known compounds used in microresistformation or the like which generate an acid upon irradiation with anactinic ray, e.g., a radiation, or far ultraviolet light having awavelength of preferably 250 nm or shorter, more preferably 220 nm orshorter, such as KrF, ArF, or F₂ excimer laser light, X-rays, orelectron beams, and mixtures of two or more thereof.

Examples thereof include diazonium salts, phosphonium salts, sulfoniumsalts, iodonium salts, imidesulfonates, oximesulfonates,diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

Also usable are compounds obtained by incorporating any of those groupsor compounds which generate an acid upon irradiation with an actinic rayinto the main chain or side chains of a polymer. Examples thereof aregiven in, e.g., U.S. Pat. No. 3,849,137, German Patent 3,914,407,JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038,JP-A-63-163452, JP-A-62-153853, and JP-A-63-146029.

Also usable are those compounds generating an acid by the action oflight which are described in U.S. Pat. No. 3,779,778 and European Patent126,712.

Preferred examples of the compound which generates an acid uponirradiation with an actinic ray include compounds represented by thefollowing general formulae (ZI), (ZII), and (ZIII).

In general formula (ZI), R₂₀₁, R₂₀₂, and R₂₀₃ each independentlyrepresent an organic group.

X⁻ represents a non-nucleophilic anion.

The organic groups represented by R₂₀₁, R₂₀₂, and R₂₀₃ each havegenerally 1 to 30, preferably 1 to 20 carbon atoms.

Two of R₂₀₁ to R₂₀₃ may be bonded to each other to form a ringstructure, which may contain an oxygen atom, sulfur atom, ester bond,amide bond, or carbonyl group therein.

Examples of the group formed by the bonding of two of R₂₀₁ to R₂₀₃include alkylene groups (e.g., butylene and pentylene).

Specific examples of the organic groups represented by R₂₀₁, R₂₀₂, andR₂₀₃ include the corresponding groups in the compounds (Z1-1), (Z1-2),and (Z1-3) which will be described later.

A compound having two or more structures represented by general formula(ZI) may also be used. For example, use may be made of a compound havinga structure in which at least one of the R₂₀₁ to R₂₀₃ of a compoundrepresented by general formula (ZI) is bonded to at least one of theR₂₀₁ to R₂₀₃ of another compound represented by general formula (ZI).

More preferred examples of ingredient (ZI) include the compounds (Z1-1),(Z1-2), and (Z1-3) which will be explained below.

Compound (Z1-1) is an arylsulfonium compound represented by generalformula (ZI) wherein at least one of R₂₀₁ to R₂₀₃ is an aryl group,i.e., a compound including an arylsulfonium as a cation.

The arylsulfonium compound may be one in which all of R₂₀₁ to R₂₀₃ arearyl groups, or may be one in which part of R₂₀₁ to R₂₀₃ is an arylgroup and the remainder is an alkyl or cycloalkyl group.

Examples of the arylsulfonium compound include triarylsulfoniumcompounds, diarylalkyl- or diarylcycloalkylsulfonium compounds, andaryldialkyl- or aryldicycloalkylsulfonium compounds.

The aryl group of the arylsulfonium compound preferably is phenyl ornaphthyl, and more preferably is phenyl. In the case where thearylsulfonium compound has two or more aryl groups, these aryl groupsmay be the same or different.

The alkyl group which is optionally possessed by the arylsulfoniumcompound preferably is a linear or branched alkyl group having 1 to 15carbon atoms. Examples thereof include methyl, ethyl, propyl, n-butyl,sec-butyl, and t-butyl.

The cycloalkyl group which is optionally possessed by the arylsulfoniumcompound preferably is a cycloalkyl group having 3 to 15 carbon atoms.Examples thereof include cyclopropyl, cyclobutyl, and cyclohexyl.

The aryl, alkyl, and cycloalkyl groups represented by R₂₀₁ to R₂₀₃ mayhave substituents selected from alkyl groups (e.g., ones having 1 to 15carbon atoms), cycloalkyl groups (e.g., ones having 3 to 15 carbonatoms), aryl groups (e.g., ones having 6 to 14 carbon atoms), alkoxygroups (e.g., ones having 1 to 15 carbon atoms), halogen atoms,hydroxyl, and phenylthio. Preferred examples of the substituents arealkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms. Mostpreferred are alkyl groups having 1 to 4 carbon atoms and alkoxy groupshaving 1 to 4 carbon atoms. One or more of such substituents may bebonded to any one of R₂₀₁ to R₂₀₃ or to each of R₂₀₁ to R₂₀₃. In thecase where R₂₀₁ to R₂₀₃ are aryl groups, it is preferred that asubstituent be bonded to the p-position in each aryl group.

Examples of the non-nucleophilic anion represented by X⁻ include asulfonic acid anion, carboxylic acid anion, sulfonylimide anion,bis(alkylsulfonyl)imide anion, and tris(alkylsulfonyl)methyl anion.

A non-nucleophilic anion is an anion the ability of which to cause anucleophilic reaction is exceedingly low and which can be inhibited frombeing decomposed by an intramolecular nucleophilic reaction with thelapse of time. This anion improves the long-term stability of resists.

Examples of the sulfonic acid anion include aliphatic sulfonic acidanions, aromatic sulfonic acid anions, and a camphorsulfonic acid anion.

Examples of the carboxylic acid anion include aliphatic carboxylic acidanions, aromatic carboxylic acid anions, and aralkylcarboxylic acidanions.

Examples of the aliphatic hydrocarbon groups in the aliphatic sulfonicacid anions include alkyl groups preferably having 1 to 30 carbon atoms,such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl,pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl,tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl,nonadecyl, and eicosyl, and cycloalkyl groups preferably having 3 to 30carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, adamantyl,norbornyl, and bornyl.

Examples of the aromatic groups in the aromatic sulfonic acid anionsinclude aryl groups preferably having 6 to 14 carbon atoms, such asphenyl, tolyl, and naphthyl.

The alkyl, cycloalkyl, and aryl groups in the aliphatic sulfonic acidanions and aromatic sulfonic acid anions may have substituents.

Examples of the substituents include halogen atoms, alkyl groups, alkoxygroups, and alkylthio groups.

Examples of the halogen atoms include chlorine, bromine, fluorine, andiodine atoms.

Examples of the alkyl groups include alkyl groups preferably having 1 to15 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl,isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl,decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl,heptadecyl, octadecyl, nonadecyl, and eicosyl.

Examples of the alkoxy groups include alkoxy groups preferably having 1to 5 carbon atoms, such as methoxy, ethoxy, propoxy, and butoxy.

Examples of the alkylthio groups include alkylthio groups preferablyhaving 1 to 15 carbon atoms, such as methylthio, ethylthio, propylthio,isopropylthio, n-butylthio, isobutylthio, sec-butylthio, pentylthio,neopentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio,undecylthio, dodecylthio, tridecylthio, tetradecylthio, pentadecyltio,hexadecylthio, heptadecylthio, octadecylthio, nonadecylthio, andeicosylthio. The alkyl, alkoxy, and alkylthio groups may be furthersubstituted with halogen atoms (preferably fluorine atoms).

Examples of the aliphatic hydrocarbon groups in the aliphatic carboxylicacid anions include the same aliphatic hydrocarbon groups as in thealiphatic sulfonic acid anions.

Examples of the aromatic groups in the aromatic carboxylic acid anionsinclude the same aromatic groups as in the aromatic sulfonic acidanions.

Examples of the aralkyl groups in the aralkylcarboxylic acid anionsinclude aralkyl groups preferably having 6 to 12 carbon atoms, such asbenzyl, phenethyl, naphthylmethyl, naphthylethyl, and naphthylbutyl.

The alkyl, cycloalkyl, aryl, and aralkyl groups in the aliphaticcarboxylic acid anions, aromatic carboxylic acid anions, andaralkylcarboxylic acid anions may have substituents. Examples of thesubstituents include the same halogen atoms, alkyl groups, alkoxygroups, and alkylthio groups as in the aliphatic sulfonic acid anionsand aromatic sulfonic acid anions.

Examples of the sulfonylimide anion include a saccharin anion.

The alkyl groups in the bis(alkylsulfonyl)imide anion andtris(alkylsulfonyl)methyl anion preferably are alkyl groups having 1 to5 carbon atoms. Examples thereof include methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, and neopentyl. Thesealkyl groups may have substituents. Examples of the substituents includehalogen atoms, alkyl groups substituted with one or more halogen atoms,alkoxy groups, and alkylthio groups. Preferred are alkyl groupssubstituted with one or more fluorine atoms.

Other examples of the non-nucleophilic anion include phosphorusfluoride, boron fluoride, and antimony fluoride.

The non-nucleophilic anion represented by X⁻ preferably is an aliphaticsulfonic acid anion substituted with one or more fluorine atoms, anaromatic sulfonic acid anion substituted with one or more fluorine atomsor fluorinated groups, a bis(alkylsulfonyl)imide anion in which thealkyl groups are substituted with one or more fluorine atoms, or atris(alkylsulfonyl)methyl anion in which the alkyl groups aresubstituted with one or more fluorine atoms. The non-nucleophilic anionrepresented by X⁻ more preferably is a fluorine-substituted aliphaticsulfonic acid anion having 4 to 8 carbon atoms, and especiallypreferably is a nonafluorobutanesulfonic acid anion orperfluorooctanesulfonic acid anion.

Next, compound (Z1-2) will be explained.

Compound (Z1-2) is a compound represented by formula (ZI) wherein R₂₀₁to R₂₀₃ each independently represent an organic group containing noaromatic ring. The term aromatic ring herein implies any of aromaticrings including ones containing one or more heteroatoms.

The organic groups containing no aromatic ring which are represented byR₂₀₁ to R₂₀₃ each have generally 1 to 30, preferably 1 to 20 carbonatoms.

Preferably, R₂₀₁ to R₂₀₃ each independently are an aliphatic hydrocarbongroup. R₂₀₁ to R₂₀₃ each more preferably are a linear, branched, orcyclic 2-oxoalkyl group or an alkoxycarbonylmethyl group, and mostpreferably are a linear or branched 2-oxoalkyl group.

The aliphatic hydrocarbon groups represented by R₂₀₁ to R₂₀₃ may be anyof linear or branched alkyl groups and cycloalkyl groups. Preferredexamples thereof include linear or branched alkyl groups having 1 to 10carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl) andcycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl,cyclohexyl, and norbornyl). More preferred aliphatic hydrocarbon groupsare 2-oxoalkyl groups and alkoxycarbonylmethyl groups.

The 2-oxoalkyl groups may be either linear or branched or cyclic.Preferred examples thereof include the alkyl and cycloalkyl groupsenumerated above which each have >C═O in the 2-position.

Examples of the alkoxy groups in the alkoxycarbonylmethyl groups includealkoxy groups preferably having 1 to 5 carbon atoms (methoxy, ethoxy,propoxy, butoxy, and pentoxy).

R₂₀₁ to R₂₀₃ may be further substituted with substituents selected fromhalogen atoms, alkoxy groups (e.g., ones having 1 to 5 carbon atoms),hydroxyl, cyano, and nitro.

Two of R₂₀₁ to R₂₀₃ may be bonded to each other to form a ringstructure, which may contain an oxygen atom, sulfur atom, ester bond,amide bond, or carbonyl group therein. Examples of the group formed bythe bonding of two of R₂₀₁ to R₂₀₃ include alkylene groups (e.g.,butylene and pentylene).

Compound (Z1-3) is a compound represented by the following generalformula (Z1-3). Namely, it is a compound having a phenacylsulfonium saltstructure.

R_(1C) to R_(5C) each independently represent a hydrogen atom, alkylgroup, cycloalkyl group, alkoxy group, or halogen atom.

R_(6C) to R_(7C) each represent a hydrogen atom, alkyl group, orcycloalkyl group.

R_(x) and R_(y) each independently represent an alkyl group, cycloalkylgroup, allyl, or vinyl.

Two or more of R_(1C) to R_(5C) may be bonded to each other to form aring structure, and R_(x) and R_(y) may be bonded to each other to forma ring structure. These ring structures may contain an oxygen atom,sulfur atom, ester bond, or amide bond.

Zc⁻ represents a non-nucleophilic anion, which is the same as thenon-nucleophilic anion X⁻ in general formula (ZI).

The alkyl groups represented by R_(1C) to R_(7C) may be either linear orbranched. Examples thereof include linear or branched alkyl groupshaving 1 to 20 carbon atoms. Preferred examples thereof include linearor branched alkyl groups having 1 to 12 carbon atoms (e.g., methyl,ethyl, linear or branched propyl, linear or branched butyl, and linearor branched pentyl).

Examples of the cycloalkyl groups represented by R_(1C) to R_(7C)include cycloalkyl groups having 3 to 20 carbon atoms. Preferredexamples thereof include cycloalkyl groups having 3 to 8 carbon atoms(e.g., cyclopentyl and cyclohexyl).

The alkoxy groups represented by R_(1C) to R_(5C) may be either linearor branched or cyclic. Examples thereof include alkoxy groups having 1to 10 carbon atoms. Preferred examples thereof include linear orbranched alkoxy groups having 1 to 5 carbon atoms (e.g., methoxy,ethoxy, linear or branched propoxy, linear or branched butoxy, andlinear or branched pentoxy) and cyclic alkoxy groups having 3 to 8carbon atoms (e.g., cyclopentyloxy and cyclohexyloxy).

It is preferred that any of R_(1C) to R_(5C) be a linear or branchedalkyl group, cycloalkyl group, or linear, branched, or cyclic alkoxygroup. It is more preferred that the total number of carbon atoms inR_(1C) to R_(5C) be from 2 to 15. This compound has further improvedsolubility in solvents and is inhibited from generating particles duringstorage.

Examples of the alkyl groups and cycloalkyl groups represented by R_(x)and R_(y) include the same groups as those enumerated above as examplesof the alkyl groups and cycloalkyl groups represented by R_(1C) toR_(5C). Preferred are 2-oxoalkyl groups and alkoxycarbonylmethyl groups.

Examples of the 2-oxoalkyl groups include those alkyl and cycloalkylgroups represented by R_(1C) to R_(7C) which each have >C═O in the2-position.

Examples of the alkoxy groups in the alkoxycarbonylmethyl groups includethe same groups as those enumerated above as examples of the alkoxygroups represented by R_(1C) to R_(5C).

Examples of the group formed by the bonding of R_(x) and R_(y) includebutylene and pentylene.

R_(x) and R_(y) each preferably are an alkyl group having 4 or morecarbon atoms or a cycloalkyl group, and more preferably are an alkylgroup having 6 or more, especially preferably 8 or more carbon atoms ora cycloalkyl group.

In general formulae (ZII) and (ZIII), R₂₀₄ to R₂₀₇ each independentlyrepresent an aryl group, alkyl group, or cycloalkyl group.

The aryl groups represented by R₂₀₄ to R₂₀₇ preferably are phenyl ornaphthyl, and more preferably are phenyl.

The alkyl groups represented by R₂₀₄ to R₂₀₇ may be either linear orbranched. Preferred examples thereof include linear or branched alkylgroups having 1 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl,and pentyl).

Preferred examples of the cycloalkyl groups represented by R₂₀₄ to R₂₀₇include cycloalkyl groups having 3 to 10 carbon atoms (e.g.,cyclopentyl, cyclohexyl, and norbornyl).

The aryl, alkyl, and cycloalkyl groups represented by R₂₀₄ to R₂₀₇ mayhave substituents. Examples of the substituents which may be possessedby the aryl, alkyl, and cycloalkyl groups represented by R₂₀₄ to R₂₀₇include alkyl groups (e.g., ones having 1 to 15 carbon atoms),cycloalkyl groups (e.g., ones having 3 to 15 carbon atoms), aryl groups(e.g., ones having 6 to 15 carbon atoms), alkoxy groups (e.g., oneshaving 1 to 15 carbon atoms), halogen atoms, hydroxyl, and phenylthio.

X⁻ represents a non-nucleophilic anion, which is the same as thenon-nucleophilic anion X⁻ in general formula (ZI).

Other especially effective examples of the compound to be used in theinvention which decomposes upon irradiation of an actinic ray togenerate an acid include compounds represented by the following formulae(ZIV) to (ZVII).

In general formulae (ZIV) to (ZVII),

Ar₃ and Ar₄ each independently represent an aryl group.

R₂₀₆ represents an alkyl group, cycloalkyl group, or aryl group.

Symbol A represents an alkylene group, alkenylene group, or arylenegroup.

R represents an alkyl group, cycloalkyl group, or aryl group.

R₂₀₇ represents an electron-attracting group, and preferably representsa cyano or fluoroalkyl group.

R₂₀₈ represents an alkyl group, cycloalkyl group, or aryl group.

More preferred of those compounds which generate an acid uponirradiation with an actinic ray are the compounds represented by generalformulae (ZI) to (ZIII).

Even more preferred of the compounds which generate an acid uponirradiation with an actinic ray are the sulfonium salts represented bygeneral formula (ZI). Especially preferred are the sulfonium saltshaving one or more carbonyl groups. Most preferred are the compounds(Z1-2) having a 2-oxoalkyl group as any of R₂₀₁ to R₂₀₃ or the compoundsrepresented by general formula (Z1-3). Use of such a compound having acarbonyl group improves, in particular, sensitivity.

Examples of the especially preferred compounds which generate an acidupon irradiation with an actinic ray are shown below.

[2] (B) Resin Having Fluorine Atom and Having Group that IncreasesSolubility of the Resin in Alkaline Developer by the Action of Acid

The positive photosensitive composition of the invention contains afluorine atom-containing resin having a group that increases asolubility of the resin in an alkaline developer by the action of anacid (a fluorine atom-containing resin having a groups which dissociateby the action of an acid to enhance solubility in an alkaline developer)(hereinafter referred to also as “fluorine atom-containing resin”).

The fluorine atom-containing resin is a resin which has at least onefluorine atom bonded to the main chain and/or side chains thereof.Examples thereof include resins having repeating units represented byany of the following general formulae (I) to (X).

The fluorine atom-containing resin preferably is a resin having at leastone fluorine atom bonded to the main chain thereof. For example, a resinhaving at least one repeating unit represented by any of the followinggeneral formulae (I) to (III) and further having at least one repeatingunit represented by any of the following general formulae (IV) to (X) ispreferred.

Preferably, the fluorine atom-containing resin has a repeating unithaving from 1 to 3 groups represented by formula (A-1):

wherein R_(1a) represents a hydrogen atom, an alkyl group, a cycloalkylgroup, an acyl group, an alkoxycarbonyl group, or a group whichdissociates by the action of an acid. Preferably, R_(1a) represents ahydrogen atom

Examples of the repeating unit having from 1 to 3 groups represented byformula (A-1) are those represented by formulae (IV) to (VII):

In general formulae (I) to (X),

R₀ and R₁ may be the same or different and each represent a hydrogenatom, fluorine atom, alkyl group, cycloalkyl group, or aryl group.

R₂ to R₄ may be the same or different and each represent an alkyl group,cycloalkyl group, or aryl group.

R₀ and R₁, R₀ and R₂, or R₃ and R₄ may be bonded to each other to form aring.

R_(1a) represents a hydrogen atom, an alkyl group, a cycloalkyl group,an acyl group, an alkoxycarbonyl group, or a group which dissociates bythe action of an acid.

R₆, R₇, and R₈ may be the same or different and each represent ahydrogen atom, halogen atom, alkyl group, or alkoxy group.

R₉ and R₁₀ each represent a hydrogen atom, halogen atom, cyano, or alkylgroup.

R₁₁ and R₁₂ may be the same or different and each represent a hydrogenatom, hydroxyl, halogen atom, cyano, alkoxy group, acyl group, alkylgroup, cycloalkyl group, alkenyl group, aralkyl group, or aryl group.

R₁₃ and R₁₄ may be the same or different and each represent a hydrogenatom, halogen atom, cyano, or alkyl group.

R₁₅ represents a hydrogen atom, hydroxyalkyl group, alkyl group havingone or more fluorine atoms, cycloalkyl group having one or more fluorineatoms, alkenyl group having one or more fluorine atoms, aralkyl grouphaving one or more fluorine atoms, aryl group having one or morefluorine atoms, —C(R₃₆)(R₃₇)(R₃₈), —C(R₃₆)(R₃₇)(OR₃₉), or a grouprepresented by the following general formula (XI).

R₃₆, R₃₇, R₃₈, and R₃₉ may be the same or different and each representan alkyl group, cycloalkyl group, alkenyl group, aralkyl group, or arylgroup. Two of R₃₆, R₃₇, and R₃₈ or two of R₃₆, R₃₇, and R₃₉ may bebonded to each other to form a ring.

R₄₀ represents an alkyl group, cycloalkyl group, alkenyl group, alkynylgroup, aralkyl group, or aryl group.

Z represents an atomic group which constitutes a mono- or polycyclicalicyclic group in cooperation with the carbon atom.

R₁₆, R₁₇, and R₁₈ may be the same or different and each represent ahydrogen atom, halogen atom, cyano, alkyl group, alkoxy group, or—CO—O—R₁₅.

R₁₉, R₂₀, and R₂₁ may be the same or different and each represent ahydrogen atom, fluorine atom, alkyl group having one or more fluorineatoms, cycloalkyl group having one or more fluorine atoms, alkenyl grouphaving one or more fluorine atoms, aralkyl group having one or morefluorine atoms, aryl group having one or more fluorine atoms, alkoxygroup having one or more fluorine atoms, or hydroxyalkyl group.

A₁ and A₂ each represent a single bond, alkylene group, alkenylenegroup, cycloalkylene group, arylene group, bivalent alicyclic group, orbivalent connecting group formed by combining two or more of these, orrepresent —O—CO—R₂₂—, —CO—O—R₂₃—, or —CO—N(R₂₄)—R₂₅—.

R₂₂, R₂₃, and R₂₅ each represent a single bond or a bivalent alkylene,alkenylene, cycloalkylene, or arylene group which may have an ether,ester, amide, urethane, or ureido group.

R₂₄ represents a hydrogen atom, alkyl group, cycloalkyl group, aralkylgroup, or aryl group.

Symbol n represents 0 or 1; x, y, and z each represent an integer of 0to 4; and m represents 1 or 2.

In general formulae (I) to (XI),

examples of the alkyl groups include alkyl groups having 1 to 8 carbonatoms. Preferred examples thereof include methyl, ethyl, propyl,n-butyl, sec-butyl, t-butyl, hexyl, 2-ethylhexyl, and octyl.

The cycloalkyl groups may be monocyclic or polycyclic. The monocyclicgroups may be ones having 3 to 8 carbon atoms, and preferred examplesthereof include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, andcyclooctyl. The polycyclic groups may be ones having 6 to 20 carbonatoms, and preferred examples thereof include adamantyl, norbornyl,isobornyl, camphanyl, dicyclopentyl, α-pinenyl, tricyclodecanyl,tetracyclododecyl, and androstanyl. In each of those monocyclic orpolycyclic alkyl groups, one or more of the carbon atoms may have beenreplaced by a heteroatom, e.g., an oxygen atom.

Examples of the aryl groups include aryl groups having 6 to 15 carbonatoms. Preferred examples thereof include phenyl, tolyl, dimethylphenyl,2,4,6-trimethylphenyl, naphthyl, anthryl, and 9,10-dimethoxyanthryl.

Examples of the aralkyl groups include aralkyl groups having 7 to 12carbon atoms. Preferred examples thereof include benzyl, phenethyl, andnaphthylmethyl.

Examples of the alkenyl groups include alkenyl groups having 2 to 8carbon atoms. Preferred examples thereof include vinyl, allyl, butenyl,and cyclohexenyl.

Examples of the alkoxy groups include alkoxy groups having 1 to 8 carbonatoms. Preferred examples thereof include methoxy, ethoxy, n-propoxy,isopropoxy, butoxy, pentoxy, allyloxy, and octoxy.

Examples of the acyl groups include acyl groups having 1 to 10 carbonatoms. Preferred examples thereof include formyl, acetyl, propanoyl,butanoyl, pivaloyl, octanoyl, and benzoyl.

Preferred examples of the alkynyl groups include alkynyl groups having 2to 5 carbon atoms, such as ethynyl, propynyl, and butynyl.

Examples of the alkoxycarbonyl groups include isopropoxycarbonyl,t-butoxycarbonyl, t-amyloxycarbonyl, and1-methyl-1-cyclohexyloxycarbonyl. Preferred examples thereof includesecondary alkoxycarbonyl groups. More preferred examples thereof includetertiary alkoxycarbonyl groups.

Examples of the halogen atoms include fluorine, chlorine, bromine, andiodine atoms.

Preferred examples of the alkylene groups include ones having 1 to 8carbon atoms, such as methylene, ethylene, propylene, butylene,hexylene, and octylene, which may have one or more substituents.

Preferred examples of the alkenylene groups include ones having 2 to 6carbon atoms, such as ethenylene, propenylene, and butenylene, which mayhave one or more substituents.

Preferred examples of the cycloalkylene groups include ones having 5 to8 carbon atoms, such as cyclopentylene and cyclohexylene, which may haveone or more substituents.

Preferred examples of the arylene groups include ones having 6 to 15carbon atoms, such as phenylene, tolylene, and naphthylene, which mayhave one or more substituents.

The bivalent alicyclic groups may have any polycyclic structure selectedfrom bicyclic, tricyclic, and tetracyclic structures and the like. Thenumber of carbon atoms in each bivalent alicyclic group is preferablyfrom 6 to 30, more preferably from 7 to 25. Preferred examples of thebivalent alicyclic groups include an adamantane residue (a residueformed by removing two hydrogen atoms from adamantane; the same applieshereinafter), noradamantane residue, decalin residue, tricyclodecaneresidue, tetracyclododecane residue, and norbornane residue. Morepreferred examples of the bivalent alicyclic groups include anadamantane residue and a norbornane residue.

The ring formed by the bonding of R₀ and R₁, R₀ and R₂, or R₃ and R₄ is,for example, a 5- to 7-membered ring. Examples thereof include afluorine-substituted pentane ring, hexane ring, furan ring, dioxolering, and 1,3-dioxolane ring.

The ring formed by the bonding of two of R₃₆ to R₃₈ or two of R₃₆ to R₃₇and R₃₉ is, for example, a 3- to 8-membered ring. Preferred examplesthereof include a cyclopropane ring, cyclopentane ring, cyclohexanering, furan ring, and pyran ring.

Z represents an atomic group constituting a mono- or polycyclicalicyclic group. Examples of the alicyclic group formed are as follows.The monocyclic group may be one having 3 to 8 carbon atoms, andpreferred examples thereof include cyclopropyl, cyclopentyl, cyclohexyl,cycloheptyl, and cyclooctyl. The polycyclic group may be one having 6 to20 carbon atoms, and preferred examples thereof include adamantyl,norbornyl, isobornyl, camphanyl, dicyclopentyl, α-pinenyl,tricyclodecanyl, tetracyclododecyl, and androstanyl.

The alkyl, cycloalkyl, aryl, aralkyl, alkenyl, alkoxy, acyl, alkynyl,alkoxycarbonyl, alkylene, alkenylene, cycloalkylene, arylene, and othergroups described above may have no substituent or may have substituents.Examples of substituents which may be possessed by the alkyl,cycloalkyl, aryl, aralkyl, alkenyl, alkoxy, acyl, alkynyl,alkoxycarbonyl, alkylene, alkenylene, cycloalkylene, arylene, and othergroups include alkyl groups, cycloalkyl groups, aryl groups, groupshaving active hydrogen, such as amino, amide, ureido, urethane,hydroxyl, and carboxyl groups, halogen atoms (fluorine, chlorine,bromine, and iodine atoms), alkoxy groups (e.g., methoxy, ethoxy,propoxy, and butoxy), thioether groups, acyl groups (e.g., acetyl,propanoyl, and benzoyl), acyloxy groups (e.g., acetoxy, propanoyloxy,and benzoyloxy), alkoxycarbonyl groups (e.g., methoxycarbonyl,ethoxycarbonyl, and propoxycarbonyl), cyano, and nitro.

Examples of the alkyl groups, cycloalkyl groups, and aryl groups includethose shown above. The alkyl groups may be further substituted with oneor more fluorine atoms or cycloalkyl groups.

Examples of the groups which are contained in the fluorineatom-containing resin and dissociate by the action of an acid to enhancesolubility in an alkaline developer (hereinafter referred to also as“acid-dissociable groups”) include —O—C(R₃₆)(R₃₇)(R₃₈),—O—C(R₀₁)(R₀₂)(OR₃₉). —O—C(R₃₆)(R₃₇)(OR₃₉), —O—COO—C(R₃₆)(R₃₇)(R₃₈).—O—C(R₀₁)(R₀₂)COO—C(R₃₆)(R₃₇)(R₃₈), —COO—C(R₃₆)(R₃₇)(R₃₈), and—COO—C(R₃₆)(R₃₇)(OR₃₉).

R₃₆ to R₃₉ have the same meanings as the R₃₆ to R₃₉ in R₁₅ in generalformulae (VIII) and (IX). R₀₁ and R₀₂ each represent a hydrogen atom oran alkyl, cycloalkyl, alkenyl, aralkyl, or aryl group which may have oneor more of the substituents shown above.

Preferred examples thereof include ether or ester groups of a tertiaryalkyl group such as t-butyl, t-amyl, 1-alkyl-1-cyclohexyl,2-alkyl-2-adamantyl, 2-adamantyl-2-propyl, or2-(4-methylcyclohexyl)-2-propyl; acetal or acetal ester groups of1-alkoxy-1-ethoxy, tetrahydropyranyl, or the like; t-alkyl carbonategroups; and t-alkylcarbonylmethoxy groups.

The groups which dissociate by the action of an acid to enhancesolubility in an alkaline developer can be formed, for example, as—OR_(1a) groups in repeating units represented by any of generalformulae (IV) to (VII) or as —COOR₁₅ groups in repeating unitsrepresented by any of general formulae (VIII) to (IX).

Specific examples of the repeating structural units represented bygeneral formulae (I) to (X) are shown below, but the repeating units inthe invention should not be construed as being limited to theseexamples.

The fluorine atom-containing resin preferably further has repeatingunits represented by the following general formula (XII).

In general formula (XII), R_(a1) to R_(a3) each independently representa hydrogen atom, halogen atom, cyano, or alkyl group. R_(a4) representsa hydrogen atom, halogen atom, hydroxyl, cyano, alkyl group, aryl group,alkoxy group, or aralkyl group. Symbol n represents an integer of 1 to5. When n is 2 or larger, the two or more R_(a4)'s may be the same ordifferent. (Z) represents an alicyclic hydrocarbon group. Q representshydroxyl or an acid-dissociable group. L₁ and L₂ each independentlyrepresent a single bond or a bivalent connecting group.

In general formula (XII), examples of the halogen atoms represented byR_(a1) to R_(a3) and R_(a4) include fluorine, chlorine, bromine, andiodine atoms.

The alkyl groups represented by R_(a1) to R_(a3) and R_(a4) and thealkyl group in the alkoxy group represented by R_(a4) preferably arealkyl groups having 1 to 5 carbon atoms. Examples thereof includemethyl, ethyl, and propyl.

The aryl group represented by R_(a4) preferably is an aryl group having6 to 10 carbon atoms. Examples thereof include phenyl, tolyl, andnaphthyl.

The aralkyl group represented by R_(a4) preferably is an aralkyl grouphaving 7 to 12 carbon atoms. Examples thereof include benzyl, phenethyl,naphthylmethyl, and naphthylethyl.

The alkyl, alkoxy, aryl, aralkyl, and other groups represented by R_(a1)to R_(a3) and R_(a4) may have no substituent or may have substituents.

Examples of substituents which may be possessed by the alkyl, alkoxy,aryl, aralkyl, and other groups represented by R_(a1) to R_(a3) andR_(a4) include halogen atoms, e.g., chlorine, hydroxyl, alkoxy groups(preferably having 1 to 3 carbon atoms), and cyano.

R_(a4) preferably is a hydrogen atom, fluorine atom, trifluoromethyl,hydroxyl, cyano, methyl, or ethyl.

Examples of the alicyclic hydrocarbon group represented by (Z) includeones generally having 7 to 30 carbon atoms, preferably having 7 to 20carbon atoms, more preferably having 7 to 15 carbon atoms. The alicyclichydrocarbon group may be monocyclic or polycyclic. Specific examplesthereof include a cycloheptane residue, cyclooctane residue, norbornaneresidue, adamantane residue, tricyclodecane residue, andtetracyclododecane residue. Preferred examples thereof include anorbornane residue, adamantane residue, tricyclodecane residue, andtetracyclododecane residue.

Examples of the acid-dissociable group represented by Q include theacid-dissociable groups enumerated above.

Examples of the bivalent connecting groups represented by L₁ and L₂include alkylene groups, cycloalkylene groups, alkenylene groups,arylene groups, —O—R_(22a)—, —O—CO—R_(22b)—, —CO—O—R_(22c)—, and—CO—N(R_(22d))—R_(22e)—, which each may have one or more substituents.R_(22a), R_(22b), R_(22c), and R_(22e) each represent a single bond or abivalent alkylene, cycloalkylene, alkenylene, or arylene group which mayhave an ether, ester, amide, urethane, or ureido group. R_(22d)represents a hydrogen atom or an alkyl, cycloalkyl, aralkyl, or arylgroup which may have one or more substituents.

Examples of the alkylene group include linear and branched alkylenegroups. Specific examples thereof include ones having 1 to 8 carbonatoms, such as methylene, ethylene, propylene, butylene, hexylene, andoctylene.

Examples of the cycloalkylene group include monocyclic residues such ascyclopentylene and cyclohexylene and polycyclic residues such as anorbornane framework and adamantane framework (each having 5 to 12carbon atoms).

Preferred examples of the alkenylene group include ones having 2 to 6carbon atoms, such as ethenylene, propenylene, and butenylene, which mayhave one or more substituents.

Examples of the arylene group include ones having 6 to 15 carbon atoms,such as phenylene, tolylene, and naphthylene, which may have one or moresubstituents.

Examples of substituents which may be possessed by the bivalentconnecting groups represented by L₁ and L₂ include halogen atoms such asfluorine and chlorine atoms and cyano. Fluorine atoms are preferred.

Specific examples of the repeating structural units represented bygeneral formula (XII) are shown below, but the repeating units in theinvention should not be construed as being limited to these examples.

The fluorine atom-containing resin may further have at least onerepeating unit represented by the following general formulae (XIII) to(XV).

In the formulae, R₄₁ represents an alkyl group, cycloalkyl group,aralkyl group, or aryl group.

R₄₂ represents a hydrogen atom, halogen atom, cyano, or alkyl group.

A₅ represents a single bond, a bivalent alkylene, alkenylene,cycloalkylene, or arylene group, or a group represented by —O—CO—R₂₂—,—CO—O—R₂₃—, or —CO—N(R₂₄)—R₂₅—.

R₂₂, R₂₃, and R₂₅ may be the same or different, and each represent asingle bond or a bivalent alkylene, alkenylene, cycloalkylene, orarylene group which may have an ether, ester, amide, urethane, or ureidogroup.

R₂₄ represents a hydrogen atom or an alkyl, cycloalkyl, aralkyl, or arylgroup which may have one or more substituents.

Specific examples of the repeating structural units represented bygeneral formula (XIII) to (XV) are shown below, but the repeating unitsin the invention should not be construed as being limited to theseexamples.

Besides monomers for forming the repeating structural units shown above,other polymerizable monomers may be copolymerized in producing thefluorine atom-containing resin.

When the fluorine atom-containing resin is used for exposure to ArFexcimer laser, then the resin preferably has a fluorine atom-containingrepeating unit and a repeating unit with no fluorine atom.

Examples of the fluorine atom-containing repeating unit thoserepresented by formulae (I) to (VII) mentioned above. The repeatingunits of formulae (IV) to (VII) are preferred.

Examples of the repeating unit with no fluorine atom are those of thefollowing (a) to (c):

-   -   (a) monocyclic or polycyclic, alicyclic hydrocarbon        structure-having, acid-dissociating repeating unit;    -   (b) lactone structure-having repeating unit;    -   (c) monocyclic or polycyclic, alicyclic hydrocarbon structure        and hydroxyl group-having repeating unit.        (a) Monocyclic or Polycyclic, Alicyclic Hydrocarbon        Structure-Having, Acid-Dissociating Repeating Unit:

Preferably, the monocyclic or polycyclic, alicyclic hydrocarbonstructure-having, acid-dissociating repeating unit is anacid-dissociating repeating unit having an alicyclic hydrocarbonstructure represented by any of the following general formulae (pI) to(pVI):

In formulae (pI) to (pVI),

R₁₁ represents a methyl group, an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, an isobutyl group, or a sec-butylgroup; Z represents an atomic group necessary for forming a cycloalkylgroup along with the carbon atom in the formula;

R₁₂ to R₁₆ each independently represents a linear or branched alkylgroup having from 1 to 4 carbon atoms, or a cycloalkyl group, providedthat at least one of R₁₂ to R₁₄ or any of R₁₅ or R₁₆ is a cycloalkylgroup;

R₁₇ to R₂₁ each independently represents a hydrogen atom, a linear orbranched alkyl group having from 1 to 4 carbon atoms, or a cycloalkylgroup, provided that at least one of R₁₇ to R₂₁ is a cycloalkyl group,and any of R₁₉ or R₂₁ is a linear or branched alkyl group having from 1to 4 carbon atoms, or a cycloalkyl group;

R₂₂ to R₂₅ each independently represents a hydrogen atom, a linear orbranched alkyl group having from 1 to 4 carbon atoms, or a cycloalkylgroup, provided that at least one of R₂₂ to R₂₅ is a cycloalkyl group,and R₂₃ and R₂₄ may bond to each other to form a ring.

In formulae (pI) to (pVI), the alkyl group for R₁₂ to R₂₅ is a linear orbranched alkyl group having from 1 to 4 carbon atoms. It includes, forexample, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,sec-butyl, and t-butyl.

The alkyl group may be substituted, and the substituent for it includesan alkoxy group having from 1 to 4 carbon atoms, a halogen atom(fluorine, chlorine, bromine, iodine), an acyl group, an acyloxy group,a cyano group, a hydroxyl group, a carboxyl group, an alkoxycarbonylgroup, and a nitro group.

The cycloalkyl group for R₁₁ to R₂₅, and the cycloalkyl group which Zforms together with the carbon atom in the formulae may be monocyclic orpolycyclic. Concretely, it includes monocyclo, bicyclo, tricyclo andtetracyclo structures having 5 or more carbon atoms. The number of thecarbon atoms constituting the group is preferably from 6 to 30, morepreferably from 7 to 25. The cycloalkyl group may be substituted.

Preferred examples of the cycloalkyl group are adamantyl, noradamantyl,decalyl, tricyclodecanyl, tetracyclododecanyl, norbornyl, cedrolyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclodecanyl, and cyclododecanyl.More preferred are adamantyl, decalyl, norbornyl, cedrolyl, cyclohexyl,cycloheptyl, cyclooctyl, cyclodecanyl, and cyclododecanyl.

The substituent for the cycloalkyl group includes an alkyl group, ahalogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, andan alkoxycarbonyl group. The alkyl group is preferably a lower alkylgroup such as methyl, ethyl, propyl, isopropyl, and butyl. Morepreferably, it is selected from methyl, ethyl, propyl, and isopropyl.The alkoxy group may have from 1 to 4 carbon atoms, including methoxy,ethoxy, propoxy, and butoxy. The substituent for the alkyl, alkoxy andalkoxycarbonyl groups that may be optionally substituted includes ahydroxyl group, a halogen atom, and an alkoxy group.

The acid-dissociable repeating unit having the alicyclic hydrocarbonstructure represented any of formulae (pI) to (pVI) is preferably onerepresented by the following general formula (pA):

In the formula, R represents a hydrogen atom, a halogen atom, or alinear or branched alkyl group having from 1 to 4 carbon atoms; multipleRs may be the same or different;

A represents a single bond, an alkylene group, an ether group, athioether group, a carbonyl group, an ester group, an amido group, asulfonamido group, an urethane group, or an urea group, or a combinationof two or more of them;

Ra represents a group of formulae (pI) to (pVI).

The acid-dissociable repeating unit having the monocyclic or polycyclicalicyclic hydrocarbon structure is most preferably a repeating unit of2-alkyl-2-adamantyl(meth)acrylate ordialkyl(1-adamantyl)methyl(meth)acrylate.

Specific examples of the acid-dissociable repeating unit having themonocyclic or polycyclic alicyclic hydrocarbon structure are mentionedbelow.

(In the following formulae, Rx represents H or CH₃.)

(b) Lactone Structure-Having Repeating Unit:

The lactone structure-having repeating unit is, for example, a unithaving a lactone structure represented by any of the following generalformula (Lc) or the following general formulae (V-1) to (V-5):

In formula (Lc), Ra₁, Rb₁, Rc₁, Rd₁ and Re₁ each independentlyrepresents a hydrogen atom or an alkyl group. m and n each independentlyrepresents an integer of from 0 to 3; and m+n is from 2 to 6.

In formulae (V-1) to (V-5), R_(1b) to R_(5b) each independentlyrepresents a hydrogen atom, an alkyl group, a cycloalkyl group, analkoxy group, an alkoxycarbonyl group, an alkylsulfonylimino group, oran alkenyl group. Two of R_(1b) to R_(5b) may bond to each other to forma ring.

The alkyl group for Ra₁ to Re₁ in formula (Lc), and the alkyl group andthe alkyl moiety of the alkoxy group, the alkoxycarbonyl group and thealkylsulfonylimino group for R_(1b) to R_(5b) in formulae (V-1) to (V-5)may be a linear or branched alkyl group, and may be substituted.Preferred examples of the substituent for the group are a hydroxylgroup, a halogen atom, a carboxyl group, an alkoxy group, an acyl group,a cyano group, an acyloxy group, and a cycloalkyl group.

The repeating unit having the lactone structure-having group of any offormula (Lc) or formulae (V-1) to (V-5) is, for example, a unitrepresented by the following general formula (AI):

In formula (AI), R_(b0) represents a hydrogen atom, a halogen atom, oran alkyl group having from 1 to 4 carbon atoms. The alkyl group forR_(b0) may be substituted. For preferred examples of the substituent forthe alkyl group for R_(b0), referred to are those mentioned hereinabovefor the preferred examples of the substituent for theoptionally-substituted alkyl group for R_(1b) in formulae (V-1) to(V-5).

The halogen atom for R_(b0) may includes fluorine, chlorine, bromine andiodine. R_(b0) is preferably a hydrogen atom.

A_(b) represents a single bond, or a divalent group of an ether group,an ester group, a carbonyl group, an alkylene group, or theircombination.

V represents a group of formula (Lc) or formulae (V-1) to (V-5).

Specific examples of the lactone structure-having repeating unit arementioned below, to which, however, the invention should not be limited.

(In the formulae, Rx represents H or CH₃.)

(In the formulae, Rx represents H or CH₃.)

(In the formulae, Rx represents H or CH₃.)

(c) Monocyclic or Polycyclic, Alicyclic Hydrocarbon Structure andHydroxyl Group-Having Repeating Unit:

The monocyclic or polycyclic, alicyclic hydrocarbon structure andhydroxyl group-having group is, for example, adamantane skeleton-havinggroup represented by the following general formula (VII):

In formula (VII), R_(2c) to R_(4c) each independently represents ahydrogen atom or a hydroxyl group, provided that at least one of R_(2c)to R_(4c) is a hydroxyl group.

The groups of formula (VII) are preferably dihydroxy or monohydroxygroups, more preferably monohydroxy groups.

Repeating unit having the group of formula (VII) is, for example, one ofthe following general formula (AII):

In formula (AII), R_(1c) represents a hydrogen atom or a methyl group.

R_(2c) to R_(4c) each independently represents a hydrogen atom or ahydroxyl group, provided that at least one of R_(2c) to R_(4c) is ahydroxyl group. Preferably, two of R_(2c) to R_(4c) are hydroxyl groups.

Specific examples of the monocyclic or polycyclic, alicyclic hydrocarbonstructure and hydroxyl group-having repeating unit are mentioned below,to which, however, the invention should not be limited.

The fluorine atom-containing resin that has fluorine an atom-containingrepeating unit and has a repeating unit with no fluorine atom may becopolymerized with any other comonomer in addition to theabove-mentioned repeating units.

In the fluorine atom-containing resin, the total content of repeatingunits represented by general formulae (I) to (X) is generally from 2 to80% by mole, preferably from 5 to 70% by mole, more preferably from 10to 60% by mole, based on the whole polymer composition.

In the case where the fluorine atom-containing resin has repeating unitsrepresented by general formulae (I) to (III) and repeating unitsrepresented by general formulae (IV) to (X), the content of therepeating units represented by general formulae (I) to (III) isgenerally from 10 to 70% by mole, preferably from 20 to 60% by mole,more preferably from 30 to 50% by mole, based on the whole polymercomposition.

In the case where the fluorine atom-containing resin has repeating unitsrepresented by general formulae (I) to (III) and repeating unitsrepresented by general formulae (IV) to (X), the content of therepeating units represented by general formulae (IV) to (X) is generallyfrom 10 to 65% by mole, preferably from 15 to 60% by mole, morepreferably from 20 to 40% by mole, based on the whole polymercomposition.

The content of repeating units represented by general formula (XII) inthe fluorine atom-containing resin is generally from 20 to 80% by mole,preferably from 30 to 70% by mole.

The content of repeating units represented by general formulae (XIII) to(XV) in the fluorine atom-containing resin is generally from 0 to 70% bymole, preferably from 10 to 60% by mole, more preferably from 20 to 50%by mole.

When the fluorine atom-containing resin has repeating units having thegroup of formula (A-1), then the content of the repeating units havingthe group of formula (A-1) in the resin may be generally from 5 to 70mol %, but preferably from 10 to 50 mol %.

When the fluorine atom-containing resin has fluorine atom-containingrepeating units and has repeating units with no fluorine atom, then thecontent of the fluorine atom-containing repeating units in the resin maybe generally from 5 to 70 mol %, preferably from 10 to 50 mol %, morepreferably from 10 to 30 mol % of the total polymer composition.

When the fluorine atom-containing resin has fluorine atom-containingrepeating units and has repeating units with no fluorine atom, then thecontent of the repeating units with no fluorine atom in the resin may begenerally from 5 to 70 mol %, preferably from 10 to 50 mol %, morepreferably from 10 to 30 mol % of the total polymer composition.

In the fluorine atom-containing resin, the content of repeating unitshaving a group which dissociates by the action of an acid to enhancesolubility in an alkaline developer is generally from 5 to 70% by mole,preferably from 10 to 65% by mole, more preferably from 15 to 50% bymole, based on the whole polymer composition.

The repeating structural units examples of which were shown above eachmay be used alone, i.e., as the only one kind of repeating units, or maybe used as a mixture of two or more thereof.

The molecular weight of the fluorine atom-containing resin to be used isin the range of preferably from 1,000 to 200,000, more preferably from3,000 to 20,000, in terms of weight-average molecular weight. Themolecular-weight distribution thereof is in the range of generally from1 to 10, preferably from 1 to 3, more preferably from 1 to 2. Thenarrower the molecular-weight distribution, the better the resolution,resist shape, resist pattern side-wall smoothness, and roughnessdiminution.

From the standpoint of further diminishing development defects, thecontent of components having a molecular weight of 1,000 or lower in thefluorine atom-containing resin is preferably reduced to 15% by weight orlower, preferably 10% by weight or lower, more preferably 8% by weightor lower.

The diminution of low-molecular components can be accomplished by afractional treatment in which a resin obtained by a polymerizationreaction is dissolved in a good solvent and a poor solvent is added tothe solution to precipitate high-molecular components.

The amount of the fluorine atom-containing resin to be added is in therange of generally from 50 to 100% by weight, preferably from 60 to 98%by weight, more preferably from 65 to 95% by weight, based on all solidcomponents of the composition.

In the invention, the compound which generates an acid upon irradiationwith an actinic ray is incorporated in an amount of from 5 to 20 partsby weight per 100 parts by weight of the fluorine atom-containing resin.The amount of the compound per 100 parts by weight of the fluorineatom-containing resin is more preferably from 5 to 16 parts by weight,even more preferably from 6 to 15 parts by weight, most preferably from7 to 12 parts by weight. By incorporating the compound generating anacid upon irradiation with an actinic ray in an amount of from 5 to 20parts by weight per 100 parts by weight of the fluorine atom-containingresin, line edge roughness can be diminished while attaining highsensitivity and a rectangular pattern profile can be obtained.

[3] (C) Fluorochemical and/or Silicone Surfactant

The positive photosensitive composition of the invention preferablyfurther contains (C) any one of or two or more of fluorochemical and/orsilicone surfactants (fluorochemical surfactants, silicone surfactants,and surfactants containing both fluorine atoms and silicon atoms).

When the positive photosensitive composition of the invention containsthe surfactant (C), it can show satisfactory sensitivity and resolutionwhen irradiated with an exposure light having a wavelength of 250 nm orshorter, especially 220 nm or shorter, and give a resist pattern havingsatisfactory adhesion and reduced in development defects.

Examples of those surfactants (C) include the surfactants described inJP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950,JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988,JP-A-2002-277862, and U.S. Pat. Nos. 5,405,720, 5,360,692, 5,529,881,5,296,330, 5,436,098, 5,576,143, 5,294,511, and 5,824,451. It is alsopossible to use the following commercial surfactants as they are.

Examples of usable commercial surfactants include fluorochemical orsilicone surfactants such as F-Top EF301 and FE303 (manufactured by NewAkita Chemical Company), Fluorad FC430 and 431 (manufactured by Sumitomo3M Ltd.), Megafac F171, F173, F176, F189, and R08 (manufactured byDainippon Ink & Chemicals, Inc.), Surflon S-382 and SC101, 102, 103,104, 105, and 106 (manufactured by Asahi Glass Co., Ltd.), and TroysolS-366 (manufactured by Troy Chemical Co., Ltd.). Polysiloxane polymerKP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be usedas a silicone surfactant.

Also usable besides the known surfactants shown above is a surfactantcomprising a polymer having a fluoroaliphatic group and derived from afluoroaliphatic compound produced by the telomerization method (alsocalled telomer method) or oligomerization method (also called oligomermethod). The fluoroaliphatic compound can be synthesized by the methoddescribed in JP-A-2002-90991.

The polymer having a fluoroaliphatic group preferably is a copolymer ofa monomer having a fluoroaliphatic group with a poly(oxyalkylene)acrylate and/or a poly(oxyalkylene) methacrylate. This copolymer may beone in which the monomer units are randomly distributed or be a blockcopolymer. Examples of the poly(oxyalkylene) group includepoly(oxyethylene), poly(oxypropylene), and poly(oxybutylene). Thepoly(oxyalkylene) group may be a unit having, in the same chain,alkylenes having different chain lengths, such as a poly(blocks ofoxyethylene, oxypropylene, and oxyethylene) or poly(blocks ofoxyethylene and oxypropylene) group. The copolymer of a monomer having afluoroaliphatic group with a poly(oxyalkylene) acrylate (ormethacrylate) is not limited to binary copolymers, and may be acopolymer of three or more monomers which is obtained bycopolymerization in which two or more different monomers each having afluoroaliphatic group, two or more different poly(oxyalkylene)acrylates(or methacrylates), etc. are simultaneously copolymerized.

Examples of commercial surfactants include Megafac F178, F-470, F-473,F-475, F-476, and F-472 (manufactured by Dainippon Ink & Chemicals,Inc.). Examples of the polymer having a fluoroaliphatic group furtherinclude a copolymer of an acrylate (or methacrylate) having a C₆F₁₃group with a poly(oxyalkylene)acrylate (or methacrylate), a copolymer ofan acrylate (or methacrylate) having a C₆F₁₃ group withpoly(oxyethylene)acrylate (or methacrylate) andpoly(oxypropylene)acrylate (or methacrylate), a copolymer of an acrylate(or methacrylate) having a C₈F₁₇ group with a poly(oxyalkylene)acrylate(or methacrylate), and a copolymer of an acrylate (or methacrylate)having a C₈F₁₇ group with poly(oxyethylene)acrylate (or methacrylate)and poly(oxypropylene)acrylate (or methacrylate).

The amount of the surfactant (C) to be used is preferably from 0.0001 to2% by weight, more preferably from 0.001 to 1% by weight, based on thetotal amount of the positive photosensitive composition (excluding thesolvent).

[4] (D) Basic Compound

The positive photosensitive composition of the invention preferablycontains a basic composition (D) for the purpose of diminishingperformance changes with the lapse of time from exposure to heating.

Preferred examples thereof include structures represented by thefollowing formulae (A) to (E).

In formula (A), R²⁵⁰, R²⁵¹, and R²⁵² each independently are a hydrogenatom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl grouphaving 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbonatoms, provided that R²⁵⁰ and R²⁵¹ may be bonded to each other to form aring. The alkyl, cycloalkyl, and aryl groups may be unsubstituted or mayhave one or more substituents. The alkyl or cycloalkyl group having oneor more substituents preferably is an aminoalkyl group having 1 to 20carbon atoms, aminocycloalkyl group having 3 to 20 carbon atoms,hydroxyalkyl group having 1 to 20 carbon atoms, or hydroxycycloalkylgroup having 3 to 20 carbon atoms.

Those alkyl groups each may contain an oxygen, sulfur, or nitrogen atomin the alkyl chain.

(In the formulae, R²⁵³, R²⁵⁴, R²⁵⁵, and R²⁵⁶ each independentlyrepresent an alkyl group having 1 to 6 carbon atoms.)

Preferred compounds include substituted or unsubstituted guanidine,substituted or unsubstituted aminopyrrolidine, substituted orunsubstituted pyrazole, substituted or unsubstituted pyrazoline,substituted or unsubstituted piperazine, substituted or unsubstitutedaminomorpholine, substituted or unsubstituted aminoalkylmorpholines, andsubstituted or unsubstituted piperidine. More preferred compoundsinclude compounds having an imidazole structure, diazabicyclo structure,onium hydroxide structure, onium carboxylate structure, trialkylaminestructure, aniline structure, or pyridine structure, alkylaminederivatives having a hydroxyl group and/or ether bond, and anilinederivatives having a hydroxyl group and/or ether bond.

Examples of the compounds having an imidazole structure includeimidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of thecompounds having a diazabicyclo structure include1,4-diazabicyclo[2.2.2]octane, 1,5-diazabicyclo[4.3.0]non-5-ene, and1,8-diazabicyclo[5.4.0]undec-7-ene. Examples of the compounds having anonium hydroxide structure include triarylsulfonium hydroxides,phenacylsulfonium hydroxide, and sulfonium hydroxides having a2-oxoalkyl group, and specific examples thereof includetriphenylsulfonium hydroxide, tris(t-butylphenyl)sulfonium hydroxide,bis(t-butylphenyl)iodonium hydroxide, phenacylthiophenium hydroxide, and2-oxopropylthiophenium hydroxide. The compounds having an oniumcarboxylate structure are those compounds having an onium hydroxidestructure in which the anion part has been replaced by a carboxylate,and examples thereof include acetates, adamantane-1-carboxylates, andperfluoroalkylcarboxylates. Examples of the compounds having atrialkylamine structure include tri(n-butyl)amine and tri(n-octyl)amine.Examples of the aniline compounds include 2,6-diisopropylaniline andN,N-dimethylaniline. Examples of the alkylamine derivatives having ahydroxyl group and/or ether bond include ethanolamine, diethanolamine,triethanolamine, and tris(methoxyethoxyethyl)amine. Examples of theaniline derivatives having a hydroxyl group and/or ether bond includeN,N-bis(hydroxyethyl)aniline.

Those basic compounds may be used alone or in combination of two or morethereof. The amount of the basic compounds to be used is generally from0.001 to 10% by weight, preferably from 0.01 to 5% by weight, based onthe solid components of the positive photosensitive composition. Fromthe standpoint of sufficiently obtaining the effect of the addition, theamount of the compounds is preferably 0.001% by weight or larger. Fromthe standpoints of sensitivity and the developability of unexposedareas, the amount of the compounds is preferably 10% by weight orsmaller.

[5] Organic Solvent

The positive photosensitive composition of the invention to be used isprepared by dissolving the ingredients described above in a givenorganic solvent.

Examples of usable organic solvents include ethylene dichloride,cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methylethyl ketone, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl etheracetate, propylene glycol monomethyl ether, propylene glycol monomethylether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate,methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethylpyruvate, propyl pyruvate, N,N-dimethylformamide, dimethyl sulfoxide,N-methylpyrrolidone, and tetrahydrofuran.

In the invention, such organic solvents may be used alone or as amixture of two or more thereof. It is, however, preferred to use a mixedsolvent prepared by mixing at least one solvent containing one or morehydroxyl groups in the structure with at least one solvent containing nohydroxyl group. Use of this mixed solvent is effective in diminishingparticle generation during resist fluid storage.

Examples of the solvent containing one or more hydroxyl groups includeethylene glycol, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, propylene glycol, propylene glycol monomethyl ether,propylene glycol monoethyl ether, and ethyl lactate. Especiallypreferred of these are propylene glycol monomethyl ether and ethyllactate.

Examples of the solvent containing no hydroxyl group include propyleneglycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone,γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone,N,N-dimethylacetamide, and dimethyl sulfoxide. Especially preferred ofthese are propylene glycol monomethyl ether acetate, ethylethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butylacetate. Most preferred are propylene glycol monomethyl ether acetate,ethyl ethoxypropionate, and 2-heptanone.

The proportion (by weight) of the solvent containing one or morehydroxyl groups to the solvent containing no hydroxyl group is generallyfrom 1/99 to 99/1, preferably from 10/90 to 90/10, more preferably from20/80 to 60/40. A mixed solvent in which the content of the solventcontaining no hydroxyl group is 50% by weight or higher is especiallypreferred from the standpoint of evenness of application.

In the production of precision integrated-circuit elements or in similarprocesses, the step of resist pattern formation on a substrate can beconducted in the following manner. The positive photosensitivecomposition of the invention is applied to a substrate (e.g., a siliconsubstrate coated with silicon dioxide or a transparent substrate such asa glass substrate or ITO substrate). The resultant coating is irradiatedwith an actinic ray using a drawing apparatus and then subjected toheating, development, rinsing, and drying. Thus, a satisfactory resistpattern can be formed.

The thickness of the resist film to be formed by applying the positivephotosensitive composition of the invention on a substrate and dryingthe coating is preferably from 50 to 200 nm. The resist film regulatedso as to have a thickness of from 50 to 200 nm can have improveddry-etching resistance and pattern profile and have a heightenedtransmittance.

The thickness of a resist film can be regulated by changing the solidconcentration in the composition, i.e., the concentration of theingredients other than the solvent. The solid concentration in thecomposition is preferably from 5 to 18% by weight, more preferably from7 to 15% by weight, especially preferably from 9 to 14% by weight.

As an alkaline developer for the positive photosensitive composition ofthe invention can be used an aqueous solution of an alkali such as aninorganic alkali, e.g., sodium hydroxide, potassium hydroxide, sodiumcarbonate, sodium silicate, sodium metasilicate, or ammonia water, aprimary amine, e.g., ethylamine or n-propylamine, a secondary amine,e.g., diethylamine or di-n-butylamine, a tertiary amine, e.g.,triethylamine or methyldiethylamine, an alcoholamine, e.g.,dimethylethanolamine or triethanolamine, a quaternary ammonium salt,e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, orcholine, or a cyclic amine, e.g., pyrrole or piperidine. It is alsopossible to use a developing solution prepared by adding an appropriateamount of an alcohol, e.g., isopropyl alcohol, or a surfactant, e.g., anonionic one, to an aqueous solution of any of those alkalis.

Preferred of those alkaline developers are aqueous solutions ofquaternary ammonium salts. More preferred is an aqueous solution oftetramethyl ammonium hydroxide or choline.

The alkali concentration of the alkaline developer is generally from 0.1to 20% by weight.

The pH of the alkaline developer is generally from 10.0 to 15.0.

EXAMPLES

The invention will be explained below in greater detail by reference toExamples, but the contents of the invention should not be construed asbeing limited by these Examples.

<Fluorine Atom-Containing Resins>

The structures of the fluorine atom-containing resins (FII-1) to(FII-40) used in the Examples are shown below.

The weight-average molecular weights and other properties of thefluorine atom-containing resins (FII-1) to (FII-40) are shown in Tables1 and 2.

TABLE 1 Content of Weight-average oligomers having molecular weightDispersity molecular weight Resin Mw ratio of 1,000 or lower (FII-1)15200 1.45 5 (FII-2) 24000 1.75 8 (FII-3) 18200 1.85 7 (FII-4) 165001.46 6 (FII-5) 9500 1.58 8 (FII-6) 19500 2.02 8 (FII-7) 6500 1.85 7(FII-8) 28400 1.68 9 (FII-9) 28600 1.44 5 (FII-10) 12800 1.65 8 (FII-11)16800 1.68 9 (FII-12) 28400 1.58 6 (FII-13) 19800 1.69 8 (FII-14) 87001.95 8 (FII-15) 15200 1.46 7 (FII-16) 19500 1.65 4 (FII-17) 16900 1.42 8(FII-18) 15900 1.85 9 (FII-19) 15000 1.55 4 (FII-20) 12500 1.88 8(FII-21) 25000 1.68 9 (FII-22) 16000 1.54 7 (FII-23) 14600 1.95 5(FII-24) 17500 1.48 5 (FII-25) 16500 1.52 6 (FII-26) 14600 1.63 5

TABLE 2 Weight-average molecular weight Dispersity Resin Mw ratio(FII-27) 8300 1.55 (FII-28) 8300 1.62 (FII-29) 8000 1.52 (FII-30) 92001.71 (FII-31) 10200 1.47 (FII-32) 7900 1.35 (FII-33) 6800 1.60 (FII-34)7400 1.59 (FII-35) 8300 1.70 (FII-36) 4800 1.55 (FII-37) 4700 1.51(FII-38) 6400 1.69 (FII-39) 9600 1.70 (FII-40) 4600 1.68

Examples 1 to 20 and Comparative Examples 1 and 2 Resist Preparation

The ingredients shown in Table 3 were dissolved in a solvent to preparea solution having a solid concentration of 12% by weight. This solutionwas filtered through a 0.1-μm polytetrafluoroethylene filter to preparea positive resist solution.

TABLE 3 Basic Solvent Line edge Ingredient A Ingredient B compoundSurfactant (weight Sensitivity roughness (g) (g) (g) (0.03 g) ratio)(mJ/cm²) (nm) Profile Ex. 1 z38 FII-1 DIA W-1 A1 5.2 8.6 rectangular(0.5) (10)  (0.05) (100) Ex. 2 z6 FII-2 TPI W-1 A1/B2 2.8 9.0rectangular (0.3) (10)  (0.04) (70/30) z21 (0.3) Ex. 3 z15 FII-8 TOA W-2A1/A3 6.5 7.8 rectangular (0.1) (5) (0.04) (95/5)  z40 FII-33 (0.4) (5)Ex. 4 z38 FII-11 HEP W-2 A1/B3 3.2 7.3 rectangular (0.4) (5) (0.06)(70/30) z52 FII-34 (0.4) (5) Ex. 5 z54 FII-12 DBN W-3 A1/B2 3.0 8.0rectangular (0.7) (3) (0.05) (60/40) FII-35 (7) Ex. 6 z44 FII-13 DIA W-1A1/B1 3.8 8.7 rectangular (0.6) (10) (0.04) (55/45) PEA (0.04) Ex. 7 z14FII-14 TPA W-2 A1/B2 2.9 8.2 rectangular (0.2) (7) (0.04) (60/40) z51FII-39 (0.5) (3) Ex. 8 z46 FII-16 TPSA W-4 A1/B2 2.1 9.2 rectangular(0.5) (10)  (0.1)  (65/35) z34 (0.5) Ex. 9 z13 FII-18 TBAH W-1 A1/B2 4.89.1 rectangular (0.6) (5) (0.03) (70/30) Z27 FII-1 (0.6) (5) Ex. 10 Z1FII-20 TMEA W-4 A1/B1 3.7 8.8 rectangular (0.2) (5) (0.05) (55/45) Z37FII-5 (0.4) (5) Ex. 11 Z49 FII-27 HAP W-1 A1 2.6 8.9 rectangular (0.8)(8) (0.05) (100) FII-32 (2) Ex. 12 Z18 FII-28 DBN W-2 A2/B4 7.5 7.9rectangular (0.5) (3) (0.04) (45/55) Z31 FII-27 (0.5) (7) Ex. 13 Z38FII-29 DIA W-1 A1/B2 2.2 9.0 rectangular (0.4) (5) (0.01) (70/30) Z41FII-3 PEA (0.8) (5) (0.01) Ex. 14 Z5 FII-30 PEA W-1 A1/B1 7.7 8.6rectangular (0.6) (8) (0.05) (60/40) Z38 FII-31 (0.6) (2) Ex. 15 Z6FII-38 TPI W-1 A1/B2 2.4 7.0 rectangular (0.7) (10) (0.04) (70/30) Z21(0.7) Ex. 16 Z15 FII-40 TOA W-2 A1/A3 7.8 7.6 rectangular (0.3) (8)(0.04) (95/5) Z40 FII-1 (0.4) (2) Ex. 17 Z38 FII-19 HEP W-2 A1/B3 2.88.0 rectangular (0.4) (3) (0.06) (80/20) Z52 FII-28 (0.4) (7) Ex. 18 Z54FII-11 DBN W-3 A1/B2 3.0 8.7 rectangular (0.7) (5) (0.03) (70/30) FII-3(5) Ex. 19 Z44 FII-32 DIA W-1 A1/B1 3.1 9.1 rectangular (0.8) (5) (0.04)(60/40) FII-30 PEA (5) (0.04) Ex. 20 Z14 FII-5 TPA W-2 A1/B2 3.7 7.4rectangular (0.3) (5) (0.04) (60/40) Z51 FII-28 (0.4) (5) Comp. Z38FII-1 DIA W-1 A1 8.5 13.4 rectangular Ex. 1 (0.4) (10)  (0.05) (100)Comp. Z38 FII-1 DIA W-1 A1 2.1 11.2 tapered, Ex. 2 (2.2) (10)  (0.05)(100) film thickness loss

The abbreviations used in Table 3 are as follows.

-   DBN: 1,5-diazabicyclo[4.3.0]non-5-ene-   TPI: 2,4,5-triphenylimidazole-   TPSA: triphenylsulfonium acetate-   HEP: N-hydroxyethylpiperidine-   DIA: 2,6-diisopropylaniline-   DCMA: dicyclohexylmethylamine-   TPA: tripentylamine-   TOA: tri-n-octylamine-   HAP: hydroxyantipyrine-   TBAH: tetrabutylammonium hydroxide-   TMEA: tris(methoxyethoxyethyl)amine-   PEA: N-phenyldiethanolamine-   W-1: Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc.)    (fluorochemical)-   W-2: Megafac R08 (manufactured by Dainippon Ink & Chemicals, Inc.)    (fluorochemical and silicone)-   W-3: polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical    Co., Ltd.) (silicone)-   W-4: Troysol S-366 (manufactured by Troy Chemical Co., Ltd.)-   A1: propylene glycol monomethyl ether acetate-   A2: ethyl ethoxypropionate-   A3: γ-butyrolactone-   B1: propylene glycol monomethyl ether-   B2: cyclohexanone-   B3: 2-heptanone-   B4: ethyl lactate

<Resist Evaluation>

Each positive resist solution was applied with a spin coater to asilicon wafer treated with hexamethyldisilazane. The coating was driedby heating at 120° C. for 90 seconds with a vacuum contact type hotplate to obtain a resist film having a thickness of 100 nm.

The resist film obtained was pattern-wise exposed with an illuminatorhaving a wavelength of 157 nm. Immediately after the exposure, theresist film was heated on a hot plate at 120° C. for 90 seconds. Thisresist film was developed with a 2.38% by weight aqueous solution oftetramethylammonium hydroxide for 60 seconds and then rinsed with purewater. The pattern obtained was evaluated by the following methods.

[Profile/Sensitivity]

The shapes of sections of the pattern obtained were examined with ascanning electron microscope. The minimum energy required for forming0.1-μm lines (line/space=1/1) with satisfactory resolution was taken assensitivity.

[Line Edge Roughness]

In the line pattern (line width, 100 nm; line/space=1/1),length-direction edges in an area of 5 μm were examined with alength-measuring SEM (S-8840, manufactured by Hitachi, Ltd.) to measurethe distance from the standard line where each edge was to be present.This measurement was made on 50 points. A standard deviation wasdetermined and 3σ was calculated. The smaller the value thereof, thebetter the performance.

The results of the evaluations are shown in Table 3.

It is apparent from Table 3 that the positive photosensitivecompositions of the invention have high sensitivity and are satisfactoryin line edge roughness diminution and profile.

Examples 21 to 30, and Comparative Example 3 Resist Preparation

The ingredients shown in Table 4 were dissolved in a solvent to preparea solution having a solid concentration of 6% by mass. This solution wasfiltered through a 0.1-μm polyethylene filter to prepare a positiveresist solution. Thus prepared, the positive resist solution wasevaluated according to the methods mentioned below, and the results areshown in Table 4.

TABLE 4 Basic Line Edge Ingredient A Ingredient B Compound SurfactantSensitivity Roughness (g) (10 g) (g) (0.02 g) Solvent (mJ/cm²) (nm)Profile Ex. 21 z2 (0.6) FII-41 N-1 (0.03) W-1 SL-2/4 = 29 4.9rectangular 60/40 Ex. 22 z3 (0.7) FII-42 N-2 (0.01) W-2 SL-1/3 = 28 5.3rectangular 60/40 Ex. 23 z5 (0.6) FII-43 N-3 (0.025) W-3 SL-1/2 = 30 5.5rectangular 95/5 Ex. 24 z14 (0.7) FII-44 N-4 (0.02) W-4 SL-2/4 = 27 5.5rectangular 80/20 Ex. 25 z38 (0.35) FII-45 N-2 (0.01) W-4 SL-1/2 = 295.1 rectangular z50 (0.35) N-3 (0.01) 70/30 Ex. 26 z55 (0.7) FII-46 N-6(0.03) W-4 SL-2/4 = 26 5.6 rectangular 40/60 Ex. 27 z56 (0.4) FII-47 N-7(0.01) W-1 SL-2/4 = 30 5.2 rectangular z40 (0.4) 60/40 Ex. 28 z14 (0.7)FII-48 N-1 (0.02) W-1 SL-1/2 = 27 5.1 rectangular 70/30 Ex. 29 z44 (0.6)FII-49 N-2 (0.02) W-1 SL-2/3 = 29 5.1 rectangular 90/10 Ex. 30 z58 (0.6)FII-50 N-3 (0.02) W-4 SL-2/4 = 30 5.1 rectangular 60/40 Comp. z2 (0.6)C1 N-1 (0.03) W-1 SL-2/4 = 34 9.8 rectangular Ex. 3 60/40

The structure, the weight-average molecular weight and the degree ofdispersion of the fluorine atom-containing resins (FII-41) to (FII-50)and the comparative resin (C1) in formula 4 are shown below.

The abbreviations used in Table 4 are as follows.

-   N-1: N,N-dibutylaniline-   N-2: N,N-dipropylaniline-   N-3: N,N-dihydroxyethylaniline-   N-4: 2,4,5-Triphenylimidazole-   N-5: 2,6-Diisopropylaniline-   N-6: Hydroxyantipyrine-   N-7: Tributylamine-   W-1: Megafac F176 (from Dai-Nippon Ink Chemical Industry)    (fluorine-containing surfactant)-   W-2: Megafac R08 (from Dai-Nippon Ink Chemical Industry)    (fluorine-containing silicone-based surfactant)-   W-3: Polysiloxane Polymer KP-341 (from Shin-etsu Chemical Industry)    (silicone-based surfactant)-   W-4: Troy Sol S-366 (from Troy Chemical)-   SL-1: Cyclopentanone-   SL-2: Cyclohexanone-   SL-3: 2-Methylcyclohexanone-   SL-4: Propylene glycol monomethyl ether acetate-   SL-5: Ethyl acetate-   SL-6: Propylene glycol monomethyl ether-   SL-7: 2-Heptanone-   SL-8: γ-butyrolactone-   SL-9: Propylene carbonate

In Table 4, the ratio of multiple solvents is by mass.

<Resist Evaluation>

Brewer Science's ARC29A was uniformly applied with a spin coater to asilicon wafer to a thickness of 78 nm, and dried under heat at 205° C.for 60 seconds to form an antireflection layer thereon. Next, eachpositive resist solution was, immediately after its preparation, appliedwith a spin coater to the silicon wafer, and dried at 115° C. for 90seconds (PB) to form a 170-nm resist film.

Using an ArF excimer laser stepper (by ASML, PAS5500/1100, NA=0.75 (2/3zonal illumination), the resist film was exposed through a mask appliedthereto, and immediately after the exposure, this was heated on a hotplate at 120° C. for 90 seconds (PEB). Further, this was developed withan aqueous 2.38 mas. % tetramethylammonium hydroxide solution at 23° C.for 60 seconds, rinsed with pure water for 30 seconds, and dried toobtain a resist pattern.

(Sensitivity)

The minimum energy required for reproducing an 80-nm line-and-space 1/1mask pattern indicates the sensitivity of the sample tested.

(Line Edge Roughness)

The line edge roughness of the samples tested was determined with alength-measuring scanning electronic microscope (SEM). Concretely, inthe 80-nm line-and-space 1/1 mask pattern of each sample, themachine-direction edges in an area of 5 μm were examined with alength-measuring SEM (S-8840, manufactured by Hitachi, Ltd.) to measurethe distance from the standard line where each edge was to be present.This measurement was made on 50 points. A standard deviation wasdetermined and 3σ was calculated. The smaller the value thereof, thebetter the performance.

(Profile)

The cross-sectional profile of the 80-nm line-and-space 1/1 mask patternwas analyzed with a scanning electronic microscope.

It is apparent from Table 4 that the positive photosensitivecompositions of the invention have high sensitivity and are satisfactoryin line edge roughness diminution and profile.

Immersion Exposure:

<Resist Preparation>

The ingredients of Examples 21 to 30 were dissolved in a solvent toprepare a solution having a solid concentration of 6% by mass. Thissolution was filtered through a 0.1-μm polyethylene filter to prepare apositive resist solution. Thus prepared, the positive resist solutionwas evaluated according to the method mentioned below.

<Resolution Evaluation>

An organic antireflection chemical ARC29A (from Nissan Chemical) wasapplied to a silicon wafer, and baked at 205° C. for 60 seconds to formthereon a 78-nm antireflection film. The positive resist composition wasapplied onto it, and baked at 115° C. for 60 seconds to form thereon a150-nm resist film. Using pure water for immersion therein, the waferwas subjected to two-beam interference exposure (in wet) as shown inFIG. 1. Concretely, in the two-beam interference exposure (in wet), alaser 1, a diaphragm 2, a shutter 3, three reflective mirrors 4,5,6, andcollector lens 7 were used, and the wafer 10 was exposed via a prism 8and the immersion liquid 9 (pure water). The laser 1 has a wavelength of193 nm, and the prism 8 forms a 65 nm, line-and-space pattern.Immediately after the exposure, the wafer was heated at 115° C. for 90seconds, then developed with an aqueous tetramethylammonium hydroxidesolution (2.38 mass %) for 60 seconds, rinsed with pure water, andspin-dried. Thus formed, the resist pattern was analyzed with a scanningelectronic microscope (Hitachi's S-9260), and its resolution was on alevel of 65-nm line-and-space resolution.

This confirms that the positive photosensitive compositions of theinvention have good image forming ability even in immersion exposure.

According to the invention, a positive photosensitive composition havinghigh sensitivity and satisfactory in line edge roughness diminution andprofile can be provided.

The entire disclosure of each and every foreign patent application fromwhich the benefit of foreign priority has been claimed in the presentapplication is incorporated herein by reference, as if fully set forth.

1. A positive photosensitive composition using immersion exposurecomprising: (A) 5 to 20 parts by weight of the total amount of at leastone sulfonium salt compound that generates an acid upon irradiation withan actinic ray; (B) 100 parts by weight of the total amount of at leastone fluorine atom-containing resin having a group that increasessolubility of the resin in an alkaline developer by the action of anacid, wherein at least one basic compound is contained in an amount of0.01 to 5% by weight in the positive photosensitive composition, basedon the solid components of the positive photosensitive composition, andwherein the resin (B) has a repeating unit with no fluorine atomcomprising a mixture of the following three repeating units (a), (b) and(c): (a) a monocyclic or polycyclic alicyclic hydrocarbonstructure-having, acid-dissociating repeating unit; (b) a lactonestructure-having repeating unit; and (c) a monocyclic or polycyclicalicyclic hydrocarbon structure and hydroxyl group-having repeatingunit; and a fluorine-atom containing repeating unit having from 1 to 3groups represented by formula (A-1):

wherein R_(1a) represents a hydrogen atom, an alkyl group, a cycloalkylgroup, an acyl group or an alkoxycarbonyl group; and (C) a surfactant inan amount of 0.001 to 1% by weight based on the total amount of thepositive photosensitive composition excluding solvent.
 2. The positivephotosensitive composition according to claim 1, wherein the resin (B)has a main chain to which at least one fluorine atom is bonded.
 3. Thepositive photosensitive composition according to claim 1, wherein thecompound (A) is a sulfonium salt of a fluorine-substituted aliphaticsulfonic acid having 4 to 8 carbon atoms.
 4. The positive photosensitivecomposition according to claim 1, wherein the amount of the compound (A)per 100 parts by weight of the resin (B) is from 6 to 15 parts byweight.
 5. The positive photosensitive composition according to claim 1,wherein the amount of the compound (A) per 100 parts by weight of theresin (B) is from 7 to 12 parts by weight.
 6. The positivephotosensitive composition according to claim 1, wherein the repeatingunit with no fluorine atom of resin (B) comprises at least one repeatingunit selected from the group consisting of repeating units (pA), (AI)and (AII):

wherein R represents a hydrogen atom, a halogen atom, or a linear orbranched alkyl group having from 1 to 4 carbon atoms; multiple Rs may bethe same or different; A represents a single bond, an alkylene group, anether group, a thioether group, a carbonyl group, an ester group, anamido group, a sulfonamido group, a urethane group or a urea group, or acombination of two or more of them; R_(s) represents a group of formulae(pI) to (pVI):

wherein R₁₁ represents a methyl group, an ethyl group, an n-propylgroup, an isopropyl group, an n-butyl group, an isobutyl group, or asec-butyl group; Z represents an atomic group necessary for forming acycloalkyl group which may be substituted along with the carbon atom inthe formula; R₁₂ to R₁₆ each independently represents a linear orbranched alkyl group having from 1 to 4 carbon atoms which may besubstituted or a cycloalkyl group which may be substituted, providedthat at least one of R₁₂ to R₁₄ or any of R₁₅ or R₁₆ is a cycloalkylgroup which may be substituted; R₁₇ to R₂₁ each independently representsa hydrogen atom, a linear or branched alkyl group having from 1 to 4carbon atoms which may be substituted, or a cycloalkyl group which maybe substituted, provided that at least one of R₁₇ to R₂₁ is a cycloalkylgroup which may be substituted, and any of R₁₉ to R₂₁ is a linear orbranched alkyl group having from 1 to 4 carbon atoms which may besubstituted, or a cycloalkyl group which may be substituted; R₂₂ to R₂₅each independently represents a hydrogen atom, a linear or branchedalkyl group having from 1 to 4 carbon atoms which may be substituted, ora cycloalkyl group which may be substituted, provided that at least oneof R₂₂ to R₂₅ is a cycloalkyl group which may be substituted, and R₂₃and R₂₄ may bond to each other to form a ring:

wherein, R_(b0) represents a hydrogen atom, a halogen atom, or an alkylgroup having from 1 to 4 carbon atoms which may be substituted; A_(b),represents a single bond, or a divalent group of an ether group, anester group, a carbonyl group, an alkylene group, or their combination;V represents a group of formula (L_(c)) or formulae (V-1) to (V-5);

wherein, R_(a1), R_(b1), R_(c1), R_(d1) and R_(e1) each independentlyrepresents a hydrogen atom or an alkyl group which may be substituted; mand n each independently represents an integer of from 0 to 3; and m+nis from 2 to 6; R_(1b) to R_(5b) each independently represents ahydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, analkoxycarbonyl group, an alkylsulfonylimino group, or an alkenyl group,and two of R_(1b) to R_(5b) may bond to each other to form a ring, andthe alkyl moiety of the alkoxy group, the alkoxycarbonyl group and thealkylsulfonylimino group for R_(1b) to R_(5b) may be substituted;

wherein, R_(1c) represents a hydrogen atom or a methyl group; R_(2c) toR_(4c) each independently represents a hydrogen atom or a hydroxylgroup, provided that at least one of R_(2c) to R_(4c) is a hydroxylgroup.
 7. The positive photosensitive composition according to claim 1,wherein said 5 to 20 parts by weight of the total amount of at least onesulfonium salt compound (A) comprises 5 to 20 parts by weight of asulfonium salt compound represented by formula (ZI) or (ZI-3):

wherein R₂₀₁, R₂₀₂ and R₂₀₃ each independently represents an organicgroup, at least one of R₂₀₁, R₂₀₂ and R₂₀₃ represents an aryl group, andtwo of R₂₀₁ to R₂₀₃ may be bonded to each other to form a ringstructure, which may contain an oxygen atom, a sulfur atom, an esterbond, an amide bond, or a carbonyl group therein; and X— represents anon-nucleophilic anion selected from the group consisting of analiphatic sulfonic acid anion substituted with one or more fluorineatoms, an aromatic sulfonic acid anion substituted with one or morefluorine atoms or fluorinated groups, a bis(alkylsulfonyl)imide anion inwhich the alkyl groups are substituted with one or more fluorine atoms,and a tris(alkylsulfonyl)methyl anion in which the alkyl groups aresubstituted with one or more fluorine atoms;

wherein R_(1c) to R_(5c) each independently represents a hydrogen atom,an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom;R_(6c) and R_(7c) each independently represents a hydrogen atom, analkyl group, or a cycloalkyl group; R_(x) and R_(y) each independentlyrepresents an alkyl group, a cycloalkyl group, an allyl, or a vinylgroup; two or more of R_(1c) to R_(5c) may be bonded to each other toform a ring structure, and R_(x) and R_(y) may be bonded to each otherto form a ring structure; and Zc⁻ has the same meaning as X⁻ in formula(ZI).
 8. The positive photosensitive composition according to claim 7,wherein X− represents a nonafluorobutanesulfonic acid anion.
 9. Thepositive photosensitive composition according to claim 1, furthercomprising a mixed solvent of a solvent containing one or more hydroxylgroups in the structure and a solvent containing no hydroxyl group. 10.The positive photosensitive composition according to claim 1, whereinthe repeating unit with no fluorine atom comprises (c) a monocyclic orpolycyclic, alicyclic hydrocarbon structure and hydroxyl group-havingrepeating unit.
 11. The positive photosensitive composition according toclaim 1, further comprising a basic compound, wherein the basic compoundis at least one compound selected from the group consisting of: (i) acompound having an imidazole structure, a diazabicyclo structure, anonium hydroxide structure, an onium carboxylate structure, atrialkylamine structure, an aniline structure or a pyridine structure;(ii) an alkylamine derivative having at least one of a hydroxyl groupand an ether bond; and (iii) an aniline derivative having at least oneof a hydroxyl group and an ether bond.
 12. The positive photosensitivecomposition according to claim 1, wherein the fluorine atom-containingrepeating unit constitutes from 10 to 30 mol % of the total polymercomposition.
 13. The positive photosensitive composition according toclaim 1, wherein the repeating unit with no fluorine atom comprises arepeating unit represented by formula (pA):

wherein each R independently represents a hydrogen atom, a halogen atom,or a linear or branched alkyl group having from 1 to 4 carbon atoms; Arepresents a single bond, an alkylene group, an ether group, a thioethergroup, a carbonyl group, an ester group, an amido group, a sulfonamidogroup, a urethane group, or a urea group, or a combination of two ormore of them; and Ra represents a group represented by formulae (pII):

wherein R₁₂ to R₁₄ each independently represents a linear or branchedalkyl group having from 1 to 4 carbon atoms, or a cycloalkyl group,provided that at least one of R₁₂ to R₁₄ is a cycloalkyl group.
 14. Apositive photosensitive composition using immersion exposure comprising:(A) 5 to 20 parts by weight of the total amount of at least onesulfonium salt compound that generates an acid upon irradiation with anactinic ray; (B) 100 parts by weight of the total amount of at least onefluorine atom-containing resin having a group that increases solubilityof the resin in an alkaline developer by the action of an acid, whereinat least one basic compound is contained in an amount of 0.01 to 5% byweight in the positive photosensitive composition, based on the solidcomponents of the positive photosensitive composition, and wherein theresin (B) has a repeating unit with no fluorine atom selected from thegroup consisting of (a) a monocyclic or polycyclic alicyclic hydrocarbonstructure-having, acid-dissociating repeating unit; (b) a lactonestructure-having repeating unit; and (c) a monocyclic or polycyclicalicyclic hydrocarbon structure and hydroxyl group-having repeatingunit; and a fluorine-atom containing repeating unit having from 1 to 3groups represented by formula (A-1):

wherein R_(1a) represents a hydrogen atom, an alkyl group, a cycloalkylgroup, an acyl group or an alkoxycarbonyl group; and (C) a surfactant inan amount of 0.001 to 1% by weight based on the total amount of thepositive photosensitive composition excluding solvent; wherein the resin(B) includes repeating units (pA), (AI) and (AII):

wherein R represents a hydrogen atom, a halogen atom, or a linear orbranched alkyl group having from 1 to 4 carbon atoms; multiple Rs may bethe same or different; A represents a single bond, an alkylene group, anether group, a thioether group, a carbonyl group, an ester group, anamido group, a sulfonamido group, an urethane group or a urea group, ora combination of two or more of them; Rs represents a group of formulae(pI) to (pVI):

wherein R₁₁ represents a methyl group, an ethyl group, an n-propylgroup, an isopropyl group, an n-butyl group, an isobutyl group, or asec-butyl group; Z represents an atomic group necessary for forming acycloalkyl group which may be substituted along with the carbon atom inthe formula; R₁₂ to R₁₆ each independently represents a linear orbranched alkyl group having from 1 to 4 carbon atoms which may besubstituted or a cycloalkyl group which may be substituted, providedthat at least one of R₁₂ to R₁₄ or any of R₁₅ or R₁₆ is a cycloalkylgroup which may be substituted; R₁₇ to R₂₁ each independently representsa hydrogen atom, a linear or branched alkyl group having from 1 to 4carbon atoms which may be substituted, or a cycloalkyl group which maybe substituted, provided that at least one of R₁₇ to R₂₁ is a cycloalkylgroup which may be substituted, and any of R₁₉ to R₂₁ is a linear orbranched alkyl group having from 1 to 4 carbon atoms which may besubstituted, or a cycloalkyl group which may be substituted; R₂₂ to R₂₅each independently represents a hydrogen atom, a linear or branchedalkyl group having from 1 to 4 carbon atoms which may be substituted, ora cycloalkyl group which may be substituted, provided that at least oneof R₂₂ to R₂₅ is a cycloalkyl group which may be substituted, and R₂₃and R₂₄ may bond to each other to form a ring:

wherein, R_(b0) represents a hydrogen atom, a halogen atom, or an alkylgroup having from 1 to 4 carbon atoms which may be substituted; A_(b)represents a single bond, or a divalent group of an ether group, anester group, a carbonyl group, an alkylene group, or their combination;V represents a group of formula (L_(c)) or formulae (V-1) to (V-5);

wherein, R_(a1), R_(b1), R_(c1), R_(d1) and R_(e1) each independentlyrepresents a hydrogen atom or an alkyl group which may be substituted; mand n each independently represents an integer of from 0 to 3; and m+nis from 2 to 6; R_(1b) to R_(5b) each independently represents ahydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, analkoxycarbonyl group, an alkylsulfonylimino group, or an alkenyl group,and two of R_(1b) to R_(5b) may bond to each other to form a ring, andthe alkyl moiety of the alkoxy group, the alkoxycarbonyl group and thealkylsulfonylimino group for R_(1b) to R_(5b) may be substituted;

wherein, R_(1c) represents a hydrogen atom or a methyl group; R_(2c) toR_(4c) each independently represents a hydrogen atom or a hydroxylgroup, provided that at least one of R_(2c) to R_(4c) is a hydroxylgroup.
 15. The positive photosensitive composition according to claim 1,wherein said compound (A) is a compound represented by formula (Z1-3):

wherein R_(1c) to R_(5c) each independently represents a hydrogen atom,an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom;R_(6c) and R_(7c) each independently represents a hydrogen atom, analkyl group, or a cycloalkyl group; R_(x) and R_(y) each independentlyrepresents an alkyl group, a cycloalkyl group, an allyl, or a vinylgroup; two or more of R_(1c) to R_(5c) may be bonded to each other toform a ring structure, and Rx and Ry may be bonded to each other to forma ring structure; and Zc⁻ represents a non-nucleophilic anion selectedfrom the group consisting of an aliphatic sulfonic acid anionsubstituted with one or more fluorine atoms, an aromatic sulfonic acidanion substituted with one or more fluorine atoms or fluorinated groups,a bis(alkylsulfonyl)imide anion in which the alkyl groups aresubstituted with one or more fluorine atoms, and atris(alkylsulfonyl)methyl anion in which the alkyl groups aresubstituted with one or more fluorine atoms.
 16. The positivephotosensitive composition according to claim 1, wherein the compound(A) is a sulfonium salt of an aliphatic sulfonic acid.